How does Hill Start Assist work?

Last week we looked at a more Toyota-geared feature, so this week we thought we’d take a step back again and take a closer look at a feature available in a multitude of vehicles from manufacturers across the market. So for today’s How’s This Work, we’re looking at Hill Start Assist to figure out exactly what it is and, of course, how it works.

What is Hill Start Assist?

Hill Start Assist is a safety technology feature that helps support heavier vehicles when driving on steep slopes, and often works in conjunction with Downhill Assist which is a similar feature available in vehicles as well. HAC, which stands for Hill-start Assist Control, the long-form name of the feature, is for climbing hills while DAC, Downhill Assist Control, is for the way down.

When a heavy vehicle comes upon an especially steep hill all of a sudden, the vehicle can begin to slip backwards. The same can be said for vehicles coming to a hill that is in bad weather conditions, from snow or rain and other similar hazards. HAC is there to prevent your vehicle from rolling backwards. It does this by taking control of the pressure applied to brake fluid as you move your foot from the brake to the gas.

In other words, imagine you have to come to a stop on a steep hill because a soccer ball rolls across the street. When it’s time to go again, you have to take your foot off the brake and onto the gas, so for a second or two the vehicle is neither being stopped nor propelled forward, and thus it could begin to slide backwards. HAC prevents this from happening. You can watch the vehicle below for a better explanation of how HAC works.

If you’re curious as to which vehicles available here at Wheaton Toyota on the Trail have Hill Start Assist installed be sure to give us a call. Likewise for Downhill Assist Control, which works similarly to keep your vehicle stable when descending steep or slippery hills by keeping your speed at 5km/h.